Intrapersonal comparison of initial axial length, keratometric readings, and intraocular lens power over a 6-month interval using an IOLMaster device

Abstract

Bharkbhum Khambhiphant,1 Adisai Varadisai,2 Nat Visalvate2 1Department of Ophthalmology, King Chulalongkorn Memorial Hospital, Thai Red Cross Society, 2Department of Ophthalmology, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand Purpose: In order to improve current biometry practice, we investigated changes in axial length (AL), keratometry (K), and intraocular lens (IOL) power measured by the IOLMaster in adults within a 6-month period at the outpatient eye clinic, King Chulalongkorn Memorial Hospital, Bangkok, Thailand.Patients and methods: This was a nonrandomized prospective cohort study. The AL, steepest K, flattest K, and IOL power of nondilated eyes were measured at the initial examination and later at 6 months by the IOLMaster. Changes in AL, K, and IOL power using the SRK (Sanders, Retzlaff, and Kraff)-T formula within 6 months were compared using the paired-sample t-test.Results: The study comprised 90 eyes from 90 patients. The mean age of the patients was 62.99±13.95 years (range 28–87 years). Mean values and standard deviation for AL, steepest K, flattest K, and IOL power at initial visit and 6 months later were 23.56±1.51 mm and 23.56±1.52 mm (P=1.0; 95% confidence interval [CI] -0.01 to 0), 44.94±1.37 D and 44.98±1.43 D (P=0.96; 95% CI -0.13 to 0.04), 43.85±1.43 D and 43.89±1.36 D (P=0.93; 95% CI -0.02 to 0.07), and 20.27±4.12 D and 20.15±4.51 D (P=0.99; 95% CI -0.05 to 0.29), respectively.Conclusion: There was no statistically significant difference in AL (P=1.0), both K (P=0.96, P=0.93), or IOL power (P=0.99) within the 6-month period using the IOLMaster. Remeasurement at 6 months may be required in some cases, but should not be routine. Keywords: cataract, axial length, keratometry, IOLMaster, IOL power